Power assisted vehicle steering mechanism - has bi-directional hydraulic jack applying assisting force in response to wheel movement controlling hydraulic distributor

摘要

The steering servomechanism includes a column (1) attached to the steering wheel (2) rotating the shaft (3) on which a pinion (4) is mounted. The pinion has inclined teeth engaging a rack (5) moving at right angles to the axis of the pinion. The rack is associated with a hydraulic jack to move the levers (7) attached to the vehicle front wheels (8). Two chambers (6a,6b) are alternately connected to a source of pressure (9) and reservoir (10) via a distributor (11). The distributor has a valve stem (12) axially connected to the shaft (3) of the pinion (4). Displacement of the valve stem in one direction or the other from its neutral position causes hydraulic fluid to be supplied to one or other of the two chambers (6a,6b) to assist in moving the steering in the required direction. In an alternative arrangement the servomechanism may include the commutator of a rheostat which varies the assistance provided by an electric motor in place of the hydraulic system.